Pump



y 1962 R. c. HENSHAW 3,034,444

PUMP

Filed Dec. 21, 1959 2 Sheets-Sheet 1 3,034,444 PUMP Richard C. Henshaw, Erie, Pa., assignor to Lord Manufacturing Company, Erie, Pa., a corporation of Pennsylvania Filed Dec. 21, 1959, Ser. No. 860,882 Claims. (Cl. 103-117) This invention is a rotary pump having an impeller with flexible blades which in a preferred form are defiected axially by a warped annular surface having its inner edges lying in -a horizontal plane normal to the axis of the pump and its outer edges lying on a surface which varies circumferentially around the axis of the pump alternately from one side to the opposite side of said plane.

In the drawing, FIG. 1 is an end view of the pump, FIG. 2 is a section on line 2-2 of FIG. 1, FIG. 3 is a section on line 33 of FIG. 1, FIG. 4 is a top view of the impeller, FIG. 5 is a section on line 55 of FIG. 4, FIG. 6 is a section through one-half of the pump housing showing the warped annular surface which deflects the impeller blades, FIG. 7 is a top plan of one-half of the pump housing, FIG. 8 is an end view partly broken away of a modification, FIG. 9 is a section on line 99 of FIG. 8 and FIG. 10 is a section On line 10-10 of FIG. 8.

The pump housing comprises upper and lower parts 1 and 2 respectively provided with an outlet'3 and an inlet 4. The inlet 4 is located close to the center of the housing and communicates with a chamber 5 connected with the pump cavity. The outlet 3 is located at the outer part of the pump housing and communicates with a chamber 6 connected with the pump cavity. The difference in radial distance from the center of the pump housing to the inlet and outlet is for the purpose of utilizing centrifugal force to increase the pressure at the outlet without interfering with the suction at the inlet.

At the center of the pump housing is a drive shaft 7 keyed to an impeller hub 8 to which is bonded an impeller of rubber or like elastomeric material. Adjacent the hub 8 are cylindrical sealing projections 9 and 10 which make sealing engagement with recesses 11 and 12 in the housing parts 1 and 2. Outside the cylindrical projections 9 and 10 are radially projecting spokes 13 which on the upper and lower sides carry flexible blades 14, most clearly shown in FIG. 5. The blades are generally in the form of isosceles triangles with one of the equal sides coincident with the upper or lower surface of one of the spokes, as the case may be.

The outer edges 15 of the blades have a running fit on cylindrical surfaces 15a on the pump housing. The inclined edges 16 of the blades ride on warped annular surfaces 17 on each of the housing parts. As shown more clearly in FIG. 6, the inner edges 18 of the annular surfaces lie in a plane 19-19 at right angles to the axis of the pump. The outer edges 20 of the annular surfaces 17 lie in a plane 2121 inclined to the axis of the pump at the same angle as the inclined edges 16 of the blades. By this construction, there is no deflection of the blades at the inner edges 18 of the surfaces and there is a gradually increasing deflection of the blades as the outer edges 20 are approached.

As the impeller rotates, the blades are bent ain'ally by contact with the annular surfaces 17 from the position of maximum separation illustrated at the left in FIG. 3 to the position of minimum separation illustrated at the right in FIG. 3. In the position of maximum separation, the surfaces 17 are on the sides of the plane 19-19 remote from the center of the pump while in the position of minimum separation the surfaces 17 on both end walls are on the sides of the plane 19-19 tonited States Patent 0 3,034,444 Patented May 15, 1962 ward the center of the pump. The inlet and outlet openings are located midway between these positions of mini mum and maximum deflection so that as the blades pass the inlet 4, the volume between adjacent blades is increasing, producing a suction, while as the blades pass the outlet 3, the volume between adjacent blades is decreasing, producing a pressure, forcing liquid out through the outlet. There are no abrupt changes in position of the blades which could cause objectionable stress concentration. There is no deflection at all of the blades at the center where the blades are joined to the hub.

The pump shown in FIGS. 8, 9 and 10 is particularly adapted to large sizes. The pump housing comprises an upper part 22 having a plurality of outlets 23a, 23b, 23c, 23d, 23e, 23 and a lower part 24 having a plurality of inlets 25a, 25b, 25c, 25d, 25a, 25 The inlets and outlets are arranged in pairs bearing correspondingly lettered subscripts and the pairs are equally spaced around the axis of the pump. As in the previously described construction, the inlets are located radially inward of the outlets so as to take advantage of centrifugal force in in creasing the outlet pressure without interfering with suction at the inlets.

At the center of the pump housing is a drive shaft 26 fixed to a hub 27 having bonded to its outer part sealing projections 28, 29 which respectively make sealing engagement with complementary recesses in the housing parts 22 and 24. Radially outside the sealing projections are a series of spokes 30 which on their upper and lower surfaces have flexible rubber blades 31 of the same general shape as the blades 14, although, of course, other shapes of blades could be used. The outer edges of the blades have a running fit on cylindrical surface 32 of the pump housing. The radially extending edges 33, 34 of the blades respectively engage annular surfaces 35'and 36 on the pump housing parts 22, 24. The inner edges of the surfaces 35, 36 lie in a plane at right angles to the pump shaft. Radially outward of the inner edge, the surface 35 on the housing part 22 varies periodically above and below a plane 37 and the surface 36 on the housing part 24 similarly varies periodically above and below a plane 38. This results in the axial separation between the surfaces 35 and 36, varying successively from a minimum to a maximum and back to a This variation in axial separation occurs in each of the zones associated with the respective pairs of outlets 23a, 250-23), 25 -In FIG. 10, the variation in axial separation of the surfaces is shown for the zone associated with the inlet 25a and outlet 23a and the points of minimum separation are designated by the numerals 39, 40 and the point of maximum separation is designated by the numeral 41.

In order to obtain most elficient use of the blades for pumping, the angular distance between the point of minimum separation 39 and the point of maximum axial separation 41 is equal to three times the angular separation between adjacent blades. The same angular spacing is used between the inlet 25a and the outlet 23a. The inlet and outlet are located on the same spacing with the inlet 25a being midway between the point 39 and the point 41 and the outlet 2.3a being midway between the point '41 and the point 40. As the impeller rotates in the direction of the arrow 42, it will be noted that the volume of the cavity between the points 39 and 41 is increasing, thereby producing a suction at the inlet 25a, whereas the volume between the points 41 and 40 is decreasing, thereby producing a pressure forcing fluid out through the outlet 23a. This operation is repeated for each pair of inlets and outlets. Because of the spacing, there is always at least one pair of blades between each set of inlets and outlets which is sealed so that back flow from an outlet to the associated inlet is prevented.

Each set of inlets and outlets is illustrated as functioning separately in the sense that each inlet draws in a separate stream and each outlet discharges a separate stream. The inlets or outlets or both could be manifolded into a single inlet or outlet if desired.

The number of sets of inlets and outlets will depend to some extent on the diameter and capacity of the pump. In general, as the diameter of the pump is increased, the angular spacing between adjacent blades would become smaller 'and the number of sets of inlets and outlets would increase. The maximum. number of sets of inlets and outlets would be determined by the ability of the impeller blades to follow the contour of the pump housing with satisfactory service life.

What is claimed as new is:

l. A rotary pump comprising a pump housing having a cavity defined by a circumferential wall and by spaced end walls, each end wall having a warped annular surface with the radially inner edge lying in a plane normal to the axis of the pump and the radially outer edge lying in a plane inclined at an acute angle to said first plane, the inclined planes of the respective end walls being at an acute angle to each other whereby the axial separation of the outer edges of the annular surfaces is a minimum at one side and a at the diametrically opposite side of the axis of the pump, an inlet to the pump cavity between the, region of minimum separation and the region of maximum separation, an outlet from the pump cavity between said region of maximum separation and the region of minimum separation, and an impeller having a hub with angularly spaced axially extending flexible blades capable of being bent axially and engaging the circumferential and end walls of the cavity in the region of maximum separation and bent axially by engagement with the end walls as the blades move from the region of maximum separation to the region of minimum separation.

2. The pump of claim 1 in which the annular surfaces of the end walls are formed by radially extending straight lines connecting the inner and outer edges of the annular surfaces.

3. A rotary pump comprising a pump housing having a cavity defined, by a circumferential wall and by spaced end walls, each end wall having a warped annular surface With the radially inner edge lying in a plane normal to the axis of the pump and the radially outer edge lying on a surfiace which varies circumferentially around the axis of the pump alternately from one side to the opposite side of said plane, the end walls being positioned with respect to each other so that opposed portions of the outer edges of the respective end walls are alternately on the side of said planes toward the center of the pump to provide a region of separation and bn the side of said planes remote from the center of the pump to provide a region of maximum separation, an

inlet to the pump cavity between the region ofminimum separation and the region of maximum separation, an outlet from the pump cavity between said region of maximum separation and the region of minimum separation, and an impeller having a hub with angularly spaced axially extending flexible blades capable of being bent axially and engagingthe circumferential and end walls of the cavity in the region of maximum separation and bent axially by engagement with the end .walls as the blades move firom the region of maximum separat on to the region of minimum separation.

4. A rotary pump comprising a pump housing having a cavity defined by a circumferential wall and by spaced end walls, the end walls having axially spaced opposed annular surfaces whose axial separation from each other varies periodically from a minimum to a maximum and back to a minimum in a plurality of successive zones spaced angularly from each other around the axis of the pump, an inlet to the pump cavity in each zone between the region of minimum separation and the region of maximum separation for its zone, an outlet from the pump cavity in each zone between the region of maximum separation and the region of minimum separation for its zone, and an impeller having a hub with angularly spaced axially extending flexible blades capable of being bent axially and engaging the circumferential and end walls of the cavity in the region of maximum separation and bent axially by engagement with the end walls as the blades move from the region of maximum separation to the region of minimum separation.

5. A rotary pump comprisinga pump housing having a cavity defined by a circumferential Wall and by spaced end walls, the end walls having axially spaced opposed annular surfaces whose axial separation from each other varies periodically from a minimum to a maximum and back to a in a plurality of successive zones spaced angularly from each'other around the axis of the pump, an inlet to the pump cavity in each zone between the region of minimum separation and the region of maximum separation for its zone, an outlet from the pump cavity in each zone between the region of maximum separation and the region of minimum separation for its zone, and an impeller having a hub with angularly spaced axially extending flexible blades capable of being bent axially and engaging the circumferential and end walls of the cavity in the region of maximum separation and bent axially by engagement with the end walls as the blades move from the region of maximum separation to the region of minimum separation, the angular spacing of the blades being substantially one third the distance between the regions of minimum and maximum separation in each zone.

References Cited in the file of this patent UNITED STATES PATENTS 197,166 Ortmans Nov. 13, 1877 497,109 Wilson May 9, 1893 2,052,474 Johnson Aug. 25, 1936 2,097,714 Ayre Nov. 2, 1937 2,436,285 Booth Feb. 17, 1948 2,542,240 Fernstrum Feb. 20, 1951 2,542,268 Weyer Feb. 20, 1951 2,557,427 Gibson June 19, 1951 2,573,819 Weyer Nov. 6, 1951 2,649,052 Weyer Aug. 18, 1953 2,669,188 McIntyre Feb. 16, 1 954 2,734,457 'Fernstrum Feb. 14, 1956 2,948,227 Neely Aug. 9, 19.60

FOREIGN PATENTS 732,694 France June 20, 1932 

